Thermoplastic resins are widely used in all the industrial fields due to their production ease and molding ease. Since aromatic polycarbonate resins in particular exhibit excellent electrical insulating properties, heat resistance and impact resistance, they are often used in electronic parts such as semiconductors and electronic circuit boards, electronic devices and containers used for the storage and transportation of precision instruments. Since electronic parts are becoming smaller in size and more functional; a thermoplastic resin having both the electrical conductivity and stiffness of a thermoplastic resin molded article is desired. The size reduction and upgrading of electronic parts lead to the generation of heat from the electronic parts, and a gas generated from a resin molded article by a temperature rise causes instability due to the contamination of a head or the levitation of a disk in the interior parts of storage AV equipment. Therefore, outgas reduction property is required for a thermoplastic resin in use. However, there has been no resin composition which has outgas reduction property as well as electrical conductivity and stiffness up till now.
The addition of carbon black is one of the typical methods of providing electrical conductivity to thermoplastic resins. For example, there is known a resin composition which comprises an aromatic polycarbonate, polyalkylene terephthalate and carbon black having specific DBP oil absorptivity in a specific ratio and has the improved dispersibility of the carbon black (refer to Patent Document 1 and non-Patent Document 1). Although it is for sure that electrical conductivity can be easily provided by adding carbon black, this resin composition has low stiffness and therefore, is not suitable for use as an interior member for storage AV equipment.
The addition of graphite is known as means of providing stiffness and electrical conductivity to a thermoplastic resin, and a resin composition whose heat stability has been improved by using a phosphorus-based stabilizer is known (refer to Patent Document 2). Also, a resin composition whose anisotropy has been improved by adding mainly carbon fibers to a thermoplastic resin is known (refer to Patent Document 3). Conductive fillers such as the above carbon fibers, metal fibers, metal flakes, metal coated fibers including conductive titanium oxide, and metal coated flakes including conductive mica have been used to improve mechanical properties. Further, it is known that a resin composition having excellent dimensional stability and high stiffness and electrical conductivity is obtained by using a combination of carbon fibers and graphite which is a conductive filler (refer to Patent Document 4). However, it is hardly said that these documents disclose an adequate knowledge of outgas reduction and fail to disclose an effective knowledge to obtain excellent outgas reduction property.    (Patent Document 1) JP-A 2001-323150    (Patent Document 2) JP-A 2001-200153    (Patent Document 3) JP-A 2000-119405    (Patent Document 4) JP-A 10-237316    (Non-Patent Document 1) Journal of the Adhesion Society of Japan, Vol. 23, No. 3, p. 103-111 (1987)